A validating text editor displays simply as a text box into which you type the value. When you click out of the text box or click on to another field, the text is validated according to the data type specified for the property and if it does not match the validation pattern specified for that data type, an error message is displayed. The screenshots below show a validating text editor (in this case for the URI data type) in its error state and its valid state.
Validating Text Editor with an invalid value
Validating Text Editor with a valid value
When an editor is in the error state, the value in the editor will not be saved back to the topic map.